Injection water, deaeration

Cost of package boiler plants. Price includes complete boiler, feed-water deaerator, boiler feed pumps, chemical injection system, stack, and shop assembly labor. 

A consequence of the use of advanced technology in oil production from a reservoir results in increase in the corrosivity of the oil production environment. The extent of corrosion increases because (i) oil, water, and gas are present in the field. Seawater or fresh water is injected downhole to drive oil out of formation. As time passes, the amount of water to the amount of oil increases and the degree of internal corrosion increases. Water injection from seawater or fresh water sources causes souring of oilfields with H2S and increases in corrosion rate. These water sources require biocide injection and deaeration to avoid the introduction of new corrosion pathways into the existing system. Tertiary recovery techniques involve miscible and immiscible gas floods that may contain as much as 100% CO2. This leads to high corrosivity of the fluids. 

The injection water had not been deaerated. That is, it was just Mississippi River water that contained dissolved oxygen. Oxygen is highly corrosive to carbon steel. 

Wlien ejectors pull non-condensables and other vapors from a direct contact water condenser (barometric, low level jet, deaerator) there is also a release of dissolved gases, usually air, from water. This air must be added to the other known load of the ejector. Figure 6-22 presents the data of the Heat Exchange Insdtute [10] for the amount of air that can be expected to be released when cooling water is sprayed or otherwise injected into open qqae barometric or similar equipment. 

Anoxic (deoxygenated) water from the deaeration tank flows into a 1 500-L denitrification reactor containing colonies of Pseudomonas bacteria in a porous medium. Methanol is injected continuously and nitrate is converted into nitrite and then into nitrogen ... 

Water injection from seawater or fresh water sources contributes to the souring of oil fields with H2S usually resulting in an increase in the corrosion rate, which sometimes requires a complete change in corrosion strategy. These water sources may necessitate biocide injection and will require deaeration to avoid introducing a new corrosion mechanism into the existing system. Tertiary recovery techniques are often based on miscible and immiscible gas floods. These gas floods invariably contain a... 

Modifications to improve available NPSH at pump suction were carried out viz. balancing leak off line which was earlier heating the suction was routed to the deaerator, continuous cold injection was ensured at pump suction to improve transient performance, additional recirculation line was added to avoid pump operation at low flows. Operating procedures were modified and feed water heating by package boiler steam was strictly adhered to. This resulted in a delay of 8 months to put the SG in service. 

Figure 1. Effect of operating potential on the response of the poly(AMFc) modified electrode to ( ) 10 pM H2O2 and (A) 10 pL injections of water in deaerated (10 mL) 0.05 M MES pH 5.5 buffer with 0.1 M NaC104.

In RBMK reactors, oxygen (up to 0.2mg/kg) is injected into the feedwater circuit downstream from the condensate polishing system in order to prevent corrosive attack on the perlitic steels, and then removed from the water in the deaerator (Dragunov et al., 1992). Attempts have also been made to inject hydrogen as a remedy for intergranular corrosion attack on stainless steels. 

A typical polymerization run was carried outl l in a glass-lined autoclave. Deaerated water (12 liters) was charged to this 40-liter reactor and the interior space was evacuated. Next, 10 kg of dichlorotetrafluoroethane was added and maintained at 15°C followed by the addition of 144 g of CH2=CFC5Fk)H and 300 ml of M-pentane. Afterwards, a gas mixture of TFE and ethylene in a molar ratio of 81.7 18.3 was injected accompanied by stirring until a pressure of 1.29 MPa was reached. The reaction was initiated by the addition of 19.1 g of di(omega-hydroperfluorohexanoy) peroxide. A mixture of TFE Et CH2=CFC5FioH at a molar ratio of 51.5 46.3 18.3 was fed to the reactor to keep the pressure constant at 1.29 MPa. After 27 hours of polymerization reaction, while 7.6 g of the same initiator was added every 5 hours, the reaction mixture was recovered. 

Corrosion of boiler systems will be controlled by water treatment externally or internally, or both, as required. The term external treatment (pretreatment) is usually applied to clarification, softening, or demineralizing equipment, whereas the term internal treatment usually refers to treatment injected into the deaerator, feedlines, boiler, or steam condensate systems. 

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